ABB Relion 670 Series Technical Reference Manual page 26

Table of contents
20
Introduction......................................................................................785
Principle of operation.......................................................................785
Function block.................................................................................786
Input and output signals..................................................................786
Setting parameters..........................................................................787
Section 13 Scheme communication....................................................789
Scheme communication logic for distance or overcurrent
protection ZCPSCH(85)........................................................................789
Introduction......................................................................................789
Principle of operation.......................................................................790
Blocking scheme........................................................................790
Permissive underreaching scheme............................................790
Permissive overreaching scheme...............................................791
Unblocking scheme....................................................................791
Intertrip scheme..........................................................................792
Simplified logic diagram..............................................................792
Function block.................................................................................794
Input and output signals..................................................................794
Setting parameters..........................................................................795
Technical data.................................................................................795
Phase segregated scheme communication logic for distance
protection ZC1PPSCH (85)..................................................................796
Introduction......................................................................................796
Principle of operation.......................................................................796
Blocking scheme........................................................................797
Permissive underreach scheme.................................................798
Permissive overreach scheme...................................................798
Unblocking scheme....................................................................798
Intertrip scheme..........................................................................799
Simplified logic diagram..............................................................799
Function block.................................................................................801
Input and output signals..................................................................801
Setting parameters..........................................................................803
Technical data.................................................................................803
Current reversal and WEI logic for distance protection 3-phase
ZCRWPSCH (85)..................................................................................803
Introduction......................................................................................804
Principle of operation.......................................................................804
Current reversal logic.................................................................804
Weak-end infeed logic................................................................805
Technical reference manual